Semiconducting iron disilicide (β-FeSi2) films were epitaxially grown on the Ag-layer pre-coated Si(111) substrates with an initial β-FeSi2 layer by the metal–organic chemical vapor deposition method. These β-FeSi2 films had (101)-preferred orientations, and their crystal quality was improved as the growth temperature increased from 893 to 1093 K. The photoluminescence (PL) intensity of the (101)-oriented β-FeSi2 films grown at 973 K was larger than those of β-FeSi2 films at the other deposition temperatures, which indicates the decrease of the density of nonradiative recombination centers in β-FeSi2. A clear A-band emission originated from β-FeSi2 was observed for these films up to 285 K. This pronounced PL intensity enhancement from β-FeSi2 is attributed not only to the crystallinity evaluated by XRD measurement but also to the decrease in density of thermal equilibrium Si vacancy in β-FeSi2.